It's been over 7 years since the Switch was released on March 3, 2017. It's absolutely amazing how much they were able to squeeze out of it through software ingenuity, but it's potential is maxed out now. There were certainly some gameplay/enjoyment tradeoffs that had to be made in Tears of the Kingdom. It's probably financially impractical to keep getting the parts to make the "old" Switch vs. refreshing the hardware.